The invention relates to switching regulator with a push-pull converter embodied as a resonance converter, to which a clocked pre-regulator is series-connected, wherein separate primary windings are provided for the push-pull transformer. Such a switching regulator is known from DE 38 12 861.
Resonance converters of this type are known, for example, from "Proceedings of the XVth International PCI Conference", June 1988, Intertec Communications, Ventura, Calif., USA, pages 94 to 122.
It is known from German Patent Publication DE 29 41 009 C2 to series-connect a series switching regulator to a conventional push-pull converter, in particular for the purpose of processing greatly varying input voltages, for example with satellite power supplies. As a rule, the series switching regulator is pulse-width modulated as a function of the output voltage of the switching regulator. The downstream connected push-pull converter is operated either with push-pull pulses of a constant length or with pulse-width modulated pulses.